Java AWT Canvas

The Canvas class controls and represents a blank rectangular area where the application can draw or trap input events from the user. It inherits the Component class.

AWT Canvas class Declaration

Canvas Class Constructors

Sr. no.	Constructor	Description
1.	Canvas()	It constructs a new Canvas.
2.	Canvas(GraphicConfiguration config)	It constructs a new Canvas with the given Graphic Configuration object.

Class methods

Sr. no.	Method name	Description
1.	void addNotify()	It creates the canvas's peer.
2.	void createBufferStrategy (int numBuffers)	It creates a new multi buffering strategies on the particular component.
3.	void createBufferStrategy (int numBuffers, BufferCapabilities caps)	It creates a new multi buffering strategies on the particular component with the given buffer capabilities.
4.	AccessibleContext getAccessibleContext()	It gets the accessible context related to the Canvas.
5.	BufferStrategy getBufferStrategy()	It returns the buffer strategy used by the particular component.
6.	void paint(Graphics g)	It paints the canvas with given Graphics object.
7.	void pdate(Graphics g)	It updates the canvas with given Graphics object.

Method Inherited by Canvas Class

The Canvas has inherited above methods from the following classes:

lang.Component
lang.Object

Java AWT Canvas Example

In the following example, we are creating a Canvas in the Frame and painting a red colored oval inside it.

CanvasExample.java

// importing awt class
import java.awt.*;

// class to construct a frame and containing main method  
public class CanvasExample  
{  
  // class constructor 
  public CanvasExample()  
  {  

    // creating a frame
    Frame f = new Frame("Canvas Example"); 
    // adding canvas to frame 
    f.add(new MyCanvas());  

    // setting layout, size and visibility of frame
    f.setLayout(null);  
    f.setSize(400, 400);  
    f.setVisible(true);  
  }  

  // main method
  public static void main(String args[])  
  {  
    new CanvasExample();  
  }  
}  

// class which inherits the Canvas class
// to create Canvas
class MyCanvas extends Canvas  
{  
        // class constructor
        public MyCanvas() {  
        setBackground (Color.GRAY);  
        setSize(300, 200);  
     }  

     // paint() method to draw inside the canvas
  public void paint(Graphics g)  
  {  

    // adding specifications
    g.setColor(Color.red);  
    g.fillOval(75, 75, 150, 75);  
  }  
}     

Output: